Venting exposed rafter tails

[jim88]

Hi

Il be doing a full re build of my roof next week and I’m just a bit stumped on how to best vent exposed rafter tails up to the dry ridge system

Has anyone had any experience with this before

there’s no soffit etc

 

[jim88]

These seem to be popular in the US

 

[catlad]

You can use over fascia vents.

 

[^woody^]

If you use a suitable breathable membrane then you don't need to vent the roof.

You should install a timber eaves board to avoid exposed membrane from below.

 

[datarebal]

There is a in-between rafter vent system which you cut to size. It incorporates the chocolate box system .
I forget the make but it's out there
And a good breathable membrane will work too.

 

[catlad]

Which ever way you go just make sure its squirrel proof!

 

[Leofric]

Presume you will have quilt insulation at ceiling level (is it ceiling joists at wall plate level or a raised tie roof )
Best to know your proposed eaves detail comprising, vents, rafter trays, over fascia membrane support, type of breathable membrane, possible rafter soffit boards etc. before starting work on site.

 

[jim88]

Definitely, I’m sure I’ve got a family of them in the loft at my current house!

 

[jim88]

There is a in-between rafter vent system which you cut to size. It incorporates the chocolate box system .
I forget the make but it's out there
And a good breathable membrane will work too.

I will be using a good breather membrane, I’ve tried googling the chocolate box but nothing is coming up besides Cadbury’s milk tray


It’s new ceiling joists at wall plate, and yes I’ll have loft quilt.
I have no fascia and no soffits, gutter brackets are fixed to the rafter tails. Brickwork is between the rafters.
I think my best bet is to fit soffit vents in some timber noggins between the rafters. That cor a vent s400 is only available in America, that would of been perfect

 

[catlad]

Why are you not using the over fascia vent?

 

[jim88]

Why are you not using the over fascia vent?

ok so would that work if i bricked up the external face of my wall between the rafters. So my question is if i used over fascia vents would the air flow through this and then through the top of the breathable membrane down to the 50mm air gap above rafter insulation. Im probably not explaining my self the best!

 

[datarebal]

you could make do with over fascia vents, If the brickwork between rafters is a little lower than the tops of the rafters. simply cut the ofv to size and fix in between the rafters.

 

[catlad]

You could put some baton off cuts on the insides of the rafters and then use floor boards underneath which would leave the rafters partially visable and a channel for ventilation.